Evaluate effective security rules

First, let’s understand what Azure security rules are. They are guidelines or protocols that are set in place to manage access and protect data in a network. These rules help format security policies in Azure to control inbound and outbound traffic to resources like Azure virtual networks (VNet) and Azure SQL databases.

The Role of Network Security Groups

One of the primary ways to establish security rules in Azure is through Azure Network Security Groups (NSGs). NSGs are like a firewall, providing a list of inbound and outbound security rules that can be associated with a virtual machine, subnet, or both.

The rules defined in an NSG can allow or deny network traffic based on:

1. Priority: A parameter from 100 to 4096 that decides the sequence in which rules are applied, with lower numbers having higher priority.
2. Source and Destination: Defined by address prefixes such as IP addresses or Azure Virtual Network Tags.
3. Protocol: Concerns the type of traffic (TCP, UDP, ICMP, or Any).
4. Direction: Determines if the rule applies to inbound or outbound traffic.

Creating a Network Security Group Rule

Let’s walk through an example of creating a Network Security Group rule. First, navigate to the Azure portal, then select ‘Create a Resource’, followed by ‘Networking’ and then ‘Network Security Group’. After you’ve created your NSG, select it, then under ‘Settings’, select ‘Inbound security rules’, then ‘Add’.

You can then specify your parameters (source, target, protocol, port ranges, and action). Once these parameters are defined, click ‘Add’ to create the security rule.

Azure Firewall Rules

When it comes to managing Azure resources, another powerful tool is the Azure Firewall. It’s a managed, cloud-based network security service that protects your Azure Virtual Network resources. The Azure Firewall is highly available, and it uses a static public IP address for your Virtual Network resources, enabling outside firewalls to identify traffic originating from your Virtual Network.

The rules in Azure Firewall are classified as:

1. Application rule: Controls outbound access to FQDNs (fully qualified domain names).
2. Network rule: Controls outbound access based on IP address and port.
3. NAT (Network Address Translation) rule: Controls inbound access by translating the public IP and port to a private IP and port.

Now, let’s create a sample network rule in the Azure Firewall. Navigate to the Azure Firewall in the Azure portal, then under ‘Settings’, select ‘Rules’ and then ‘Add’. Select ‘Rule Type’ as ‘Network rule collection’ and provide the required information in other fields, then click ‘Add’.

Security Rules Evaluation

When evaluating security rules, Azure applies the rules in a particular order; this is known as rule processing. Azure processes the inbound security rules before the outbound ones. Within the inbound and outbound groups, Azure respects the priority of rules.

In case of conflicting rules, Azure follows these principles:

1. Deny all traffic, by default.
2. Allow rules are processed before Deny rules.
3. The most specific rule is used over others.

Understanding these principles can help you set up rules effectively as an Azure Administrator.

To conclude, security rules in Azure play a critical role in managing access and protecting data. Whether you’re enforcing rules via Network Security Groups or Azure Firewall, you must ensure that your rules are designed and organized with best practices in mind. As you prepare for the AZ-104 Microsoft Azure Administrator exam, knowing how to evaluate and apply these rules can mark a significant step towards success.

Practice Test

True/False: AZ-104 Microsoft Azure Administrator exam does not test a candidate’s ability to implement security controls in Azure.

• True
• False

Answer: False

Explanation: One essential aspect of the AZ-104 Microsoft Azure Administrator exam is to test a candidate’s ability to implement and manage security controls, and identity and access features in Azure.

Multiple Select: The following are various security controls in Azure, select the incorrect option(s):

• a) Azure Security Center
• b) Azure Firewall
• c) Azure Active Directory
• d) Azure Power Apps

Answer: d) Azure Power Apps

Explanation: Azure Power Apps is a suite of apps, services, data, and other systems that offer a rapid application development environment to build custom apps. It’s not a security control.

Single Select: What Azure service provides threat detection capabilities that use built-in behavioral analytics and machine learning to identify attacks and post-breach activity?

• a) Azure Active Directory
• b) Azure Security Center
• c) Azure Advanced Threat Protection (ATP)
• d) Azure Logic Apps

Answer: c) Azure Advanced Threat Protection (ATP)

Explanation: Azure Advanced Threat Protection uses machine learning capabilities to detect unusual behavior and malicious attacks, providing security insights.

True/False: Azure policies cannot be utilized for enforcing organizational security policies.

• True
• False

Answer: False

Explanation: Azure Policy is a powerful service in Azure that allows for policy enforcement at scale and helps to ensure compliance with corporate standards.

Multiple Select: Which are some of the core functionalities of Azure Active Directory?

• a) Identity Protection
• b) Multifactor Authentication
• c) Conditional Access Policy
• d) Creating Virtual Machines

Answer: a) Identity Protection, b) Multifactor Authentication, c) Conditional Access Policy

Explanation: Azure Active Directory is responsible for multiple security-oriented functionalities such as Identity protection, Multifactor Authentication, and Conditional Access Policies. Option d) is incorrect as it is not a functionality of Azure Active Directory.

True/False: Azure Security Center can perform automatic security assessments to identify potential vulnerabilities before they can be exploited.

• True
• False

Answer: True

Explanation: Azure Security Center uses advanced analytics and global threat intelligence to detect malicious threats and automate security assessments.

Single Select: What Azure service helps to protect web applications from common security risks such as SQL Injection and Cross-Site Scripting?

• a) Azure Security Center
• b) Azure Application Gateway
• c) Azure Web Application Firewall
• d) Azure Active Directory

Answer: c) Azure Web Application Firewall

Explanation: Azure Web Application Firewall protects your web applications from common threats such as SQL injection, cross-site scripting, and other common web exploits.

True/False: Role-based access control (RBAC) is a system that restricts network access based on the roles of individual users within an enterprise.

• True
• False

Answer: True

Explanation: Role-based access control (RBAC) is a method of regulating access to network resources based on the roles of individual users within an enterprise.

Multiple Select: Which data operations does Azure Storage Service Encryption (SSE) apply to?

• a) At rest
• b) In transit
• c) While processing
• d) All of the above

Answer: a) At rest

Explanation: Azure Storage Service Encryption (SSE) is used to encrypt data at rest.

Single Select: Which Azure service should be used to manage keys, secrets, and certificates?

• a) Azure Key Vault
• b) Azure Active Directory
• c) Azure Security Center
• d) Azure Policy

Answer: a) Azure Key Vault

Explanation: Azure Key Vault is a cloud service for securely storing and accessing secrets such as keys, passwords, certificates, etc.

Interview Questions

What is the main purpose of Network Security Groups (NSGs) in Azure?

Network Security Groups (NSGs) in Azure provides a means to enforce and control access to network resources by defining a set of security rules.

How can you check the effectiveness of Network Security Groups (NSGs) rules in Azure?

In Azure, the effectiveness of NSGs rules can be checked using the “Effective security rules” feature in the Azure portal which provides an aggregate list of all rules applied to the NSG or subnet.

What is the typical order of priority for processing network security rules in Azure?

Lower numbered rules are processed before higher numbered rules. By default, Network Security Groups in Azure have a few built-in rules with high priorities (65000 and above) that can’t be removed.

Can you use Azure Policy to enforce security rules?

Yes, Azure Policy is a service that can enforce different rules and effects over your resources, so those resources stay compliant with your corporate standards and service level agreements.

How can you permit or deny network traffic to resources in an Azure virtual network?

Network security groups are used to filter network traffic to and from Azure resources in an Azure virtual network. An NSG can contain multiple inbound and outbound security rules that enable you to filter traffic to and from resources by source and destination IP address, port, and protocol.

Do Azure’s security rules support service tags?

Yes, Azure security rules can utilize service tags to simplify security rule creation by reducing the number of security rules you must create.

In Azure, how are the overriding rules determined when there are conflicting security rules?

In Azure, when conflict occurs between security rules, the rule with the lowest priority number is enforced.

Which protocols can an Azure security rule encompass?

An Azure security rule can encompass TCP, UDP, ICMP, ESP, or ‘*’ (which stands for ‘any protocol’).

Can Network Security Group rules be applied at both the subnet and network interfaces (NIC) connected to a virtual machine?

Yes, Network Security Group rules can be associated to either subnets, individual virtual machine (VM) instances, or both.

If a security rule is not specified in Network Security Groups, how does Azure respond to the traffic by default?

Azure denies the traffic by default. An explicit rule to allow the specific traffic must be specified.

In Azure’s Network security groups, what type of rules – inbound security rules or outbound security rules have priority?

Neither has priority, inbound and outbound security rules are treated equally and are processed separately. A rule allowing incoming traffic does not automatically allow outgoing traffic.

What is the maximum limit of security rules that can be associated with a network security group?

A network security group can contain as many as 1000 security rules.

What is the key function of ‘Application security groups’ in Azure?

Application Security Groups (ASGs) in Azure are used to group VMs and define network security policies based on those groups.

Can you change the priority of Azure’s default security rules?

No, you cannot change the priority of Azure’s default security rules.

What happens if two network security group rules have the same priority?

If two network security group rules have the same priority, Azure uses the policy action (allow or deny) from the rule that was created most recently.